


// iResolution  已知
// iTime 已知 

float rand (vec3 vec){
    float random = sin(dot(vec,vec3(1.123,-1.51,2.3))) * 143758.5453;
    random = fract(random);
    return random;
}

void mainImage( out vec4 fragColor, in vec2 fragCoord ){
    vec3 color = vec3(0.0);

    vec2 st = fragCoord.xy/iResolution.xy;
    float value = rand(vec3(st,1.0));

    vec3 p = vec3(value);

    fragColor = vec4(p,1.0);
}